From: Hillf Danton <dhillf@gmail.com>
Date: Mon, 24 Oct 2011 14:58:12 +0000 (+1100)
Subject: mm/huge_memory: fix copying user highpage
X-Git-Tag: next-20111025~2^2~167
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0a31a0a3efcee5159aa29a467635b9a3f1c5cdce;p=karo-tx-linux.git

mm/huge_memory: fix copying user highpage

The THP copy-on-write handler falls back to regular-sized pages for a huge
page replacement upon allocation failure or if THP has been individually
disabled in the target VMA.  The loop responsible for copying page-sized
chunks accidentally uses multiples of PAGE_SHIFT instead of PAGE_SIZE as
the virtual address arg for copy_user_highpage().

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Acked-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 2a6f14c4bad9..7aa9a7fbd997 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -830,7 +830,7 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
 
 	for (i = 0; i < HPAGE_PMD_NR; i++) {
 		copy_user_highpage(pages[i], page + i,
-				   haddr + PAGE_SHIFT*i, vma);
+				   haddr + PAGE_SIZE * i, vma);
 		__SetPageUptodate(pages[i]);
 		cond_resched();
 	}